Solvent-Controlled Separation of Integratively Self-Sorted PdL L Coordination Cages.

The integrative implementation of multiple different components into metallosupramolecular self-assemblies requires sophisticated strategies to avoid the formation of statistical mixtures. Previously, the key focus was set on thermodynamically driven reactions of simple homoleptic into complex heteroleptic structures. Using PdL L -type coordination cages, we herein show that integrative self-sorting can be reversed by a change of solvent (from DMSO to MeCN) to favor narcissistic re-segregation into coexisting homoleptic species PdL and PdL . Full separation ("unsorting") back to a mixture of the homoleptic precursors was finally achieved by selective precipitation of PdL with anionic guest G from MeCN, keeping pure PdL in solution. When a mixture of homoleptic PdL and heteroleptic PdL L is exposed to a combination of two different di-anions (G and G) in DMSO, selective guest uptake gives rise to two defined coexisting host-guest complexes. A joint experimental and deep theoretical investigation via liquid-state integral equation theory of the reaction thermodynamics on a molecular level accompanied by solvent distribution analysis hints at solvent expulsion from PdL to favor the formation of PdL L in DMSO as the key entropic factor for determining the solvent-specific modulation of the cage conversion equilibrium.